For a battery driven mobile apparatus that plays data from a recording medium (a recording medium control apparatus), it is requested from the market to reduce power consumption of the apparatus and to increase continuous operation time of a battery.
A recording medium control apparatus of a prior art that intends to increase the operation time of a battery is disclosed in the Japanese patent laid-open publication No. Hei 07-065507. The recording medium control apparatus of the prior art will be explained below.
Data are read out from a rotation-driven disk by an optical head, and then servo control of the optical head and a spindle motor is executed based on an error signal generated from an output signal thereof. A decoding process is performed on the output signal from the optical head, the data are stored once in a memory, and then the data are read out at a speed, which is slower than the writing speed of the data outputted from the decoding part. A first period in which data recorded on the disk are read out by the optical head and written in the memory and a second period in which the reading of data is stopped and only the reading-out of the data stored in the memory is executed are set alternately. In such a manner, the optical head and the memory are controlled by a controller so that the data recorded on the disk are read out intermittently, and during the second period the servo control operation of the servo control part is stopped. This leads that the recording medium control apparatus can be reduced consumption of wasteful electric power.
The configuration of the recording medium control apparatus of the prior art is particularly effective to reduce the consumption of current as far as it handles only the data recorded contiguously such as the playback data. However, for example, in the case that an ID3 tag which is auxiliary information (data such as title name, artist name or the like) is added to the end of MP3 audio data which are playback data, it is necessary to obtain the ID3 tag which is auxiliary information, in advance to the playback so as to display the ID3 tag on a display device. Therefore a mechanical action that an optical pickup is once moved down to the end of music data by a traverse motor in order to obtain the ID3 tag before the optical pickup is put back to the head of the music data again is required. Since the traverse motor moves twice for the playback of one-piece of music and the total driving distance thereof is longer than that in the case that the traverse motor moves once from the top to the end of the MP3 data recording region, a problem that consumption of current becomes large remains.
The recording medium control apparatus of the prior art handling such the auxiliary information is explained below referring to the drawings. FIG. 10 is a block diagram showing a configuration of an optical disk controller of the prior art, FIG. 6 is a diagram showing a data configuration of the MP3 (Mpeg Audio Layer 3) data which are music data, and FIG. 7 is a diagram showing an arrangement of playback data on the playback data recording part 710 and the auxiliary information recording part 711 and an operation of an optical pickup for reading those data.
As shown in FIG. 10, the optical disk control apparatus 1000 includes a spindle motor 111, an optical pickup 112, a traverse motor 113, a system control part 114, a playback control part 1020, an auxiliary information access control-part C1021, and a playback-data access control part 122.
As shown in FIG. 6, MP3 data 610, which are music data, consists of MP3 audio data 611, which is a playback data part, and an ID3 tag 612, which is an auxiliary information part and is added to the end of the MP3 audio data 611. The ID3 tag 612, which is the auxiliary information part, is sometimes added to the head of the MP3 audio data 611. In addition, a plurality of sets of the MP3 data 610 consisting of the MP3 audio data 611 and the ID3 tag 612 are recorded on an exchangeable optical disk 110 in FIG. 10.
The optical disk control apparatus 1000 configured as described above will be explained referring to FIGS. 10, 6 and 7. In the optical disk control apparatus 1000 shown in FIG. 10, during the optical disk 110 is being rotated by the spindle motor 111, the optical pickup 112 is moved by the traverse motor 113, and then the optical pickup 112 reads out the data recorded on the optical disk 110. The system control part 114 processes the data having been read and outputs a sound L channel signal and a sound R channel signal as a playback signal. Also the system control part 114 executes focus servo control and tracking servo control of the optical pickup 112 when reading out data from the optical disk 110, rotation control of the spindle motor 111 for stable rotation of the optical disk 110, and rotation control of the traverse motor 113 to move the optical pickup 112 to a destination access position on the optical disk 110.
Hereupon, when a key-inputting from outside is made, a playback control part E1020 operates according to the key input. For example, in the case that a PLAY key-inputting is made in a stopped state, the playback control part E1020 instructs a playback-data access control part 122 to play a signal. The playback-data access control part 122 requests to the system control part 114 accessing of the playback data. The system control part 114 controls the spindle motor 111 and the traverse motor 113 according to the request to access the playback data to move the optical pickup 112 to the destination position of the playback data on the optical disk 110. The optical pickup 112 reads out the destination playback data. The system control part 114 processes the data having been read to output the sound L channel signal and the sound R channel signal as the playback signal. Furthermore, in the case that the auxiliary information (ID3 tag) is added to the playback data, the playback control part E1020 instructs the auxiliary information access control part C102 in order to obtain the auxiliary information (ID3 tag). The auxiliary information access control part C1021 requests to the system control part 114 accessing of the auxiliary information. The system control part 114 controls the spindle motor 111 and the traverse motor 113 according to the request of the auxiliary information access to move the optical pickup 112 to a position of the destination auxiliary information (ID3 tag) on the optical disk 110. The optical pickup 112 reads out the destination auxiliary information (ID3 tag). The playback control part E1020 analyzes the auxiliary information (ID3 tag) having been read to output and displays it.
FIG. 7 is a diagram showing the state in which the optical pickup 112 is moved by the traverse motor 113 to read out the playback data recording part 710 and the auxiliary information recording part 711 of the audio data of one-music-piece recorded on the optical disk 110. Contiguous recording regions, each consisting of the playback data recording part 710 and the auxiliary information recording part 711 of audio data of one-music-piece, are provided as many number as recorded number of music pieces on the optical disk 110. In FIG. 7, one of the recording regions consisting of the audio data 710 and the auxiliary information recording part 711 of one-music-piece is enlarged and shown. FIG. 7(b) is an enlarged view of a part of FIG. 7(a). In FIG. 10, in the case that the above-mentioned PLAY key-inputting is made, the playback-data access control part 122 and the auxiliary information access control part C1021 request to the system control part 114 accessing of the playback data and the auxiliary information. The playback control part E1020 is required to output the ID3 tag (e.g. title name), which is the auxiliary information, at the time of starting the playback. Therefore, as shown in FIG. 7, in the case that the MP3 data are played, the traverse motor 113 moves the optical pickup 112 not directly to a position (1), which is the head position of the MP3 audio data recorded on the playback data recording part 710, but rather to a position (3) in order to obtain the ID3 tag recorded on the auxiliary information recording part 711 according to the request of the auxiliary information access. While the traverse motor 113 moves the optical pickup 112 from the position (3) to the position (4), the optical pickup 112 reads out the ID3 tag. Then, after completion of reading the ID3 tag, the traverse motor 113 puts the optical pickup 112 back to the position (1) according to the request of the playback data access so as to play the MP3 audio data recorded in the playback data recording part 710. During the while the traverse motor 113 moves the optical pickup 112 from the position (1) to the position (2), the optical pickup 112 reads out the MP3 audio data. The system control part 114 outputs the playback signal.
In the recording medium control apparatus of the prior art, in the case that the auxiliary information ID3 tag is added at the end of the MP3 audio data which are the playback data, since the auxiliary information ID3 tag is required to be obtained prior to the playback, a mechanical action putting the optical pickup back to the head of the music data again is required after moving the optical pickup to the end of the music data once using the traverse motor and obtaining the ID3 tag. To play one-piece of music, the traverse motor 113 is driven twice, and its total driving distance is longer than that in the case that the traverse motor moves from the head to the end of the recording region of the MP3 data 610 once. Therefore, when this optical disk control apparatus operates with a battery of which power source supply capacity is finite, there has been a problem that more of the remaining capacity of the battery is consumed, and as a result, the operation duration time of the apparatus becomes short.